I have ubuntu 7.10 on my main machine (dual boot with XP) and Mint 4.0 upstairs on the old P4. Both run great. Mint was easier.
I did have PCLOS on this machine, but could not get the nvidia drivers to work, and didn't feel like spending a lot of time on line working on it. So I switched to uu7.10. I still had trouble--I had to add another repository to find the drivers. I am now wondering if that is the problem I had with PCLOS.
Everyone is hot on PCLOS, but I think really it just has a nicer control panel. Once you get things set up that is not that relevant. For me the whole point is simplicity. Get it working and use it for basic tasks. For example, if my computer is off, and all I want to do is surf the web, I'll boot up ubuntu and call it a day.